1. Field of the Invention
This invention relates to the art of prosthetic devices and methods of implanting the same in vertebrae to treat or prevent back pain in patients with ruptured or degenerated intervetebral discs. Specifically, the invention deals with a metal implant plug or block sized and shaped to form a strut between adjoining vertebrae and having a porous surface to promote bone ingrowth, and to methods of implanting the plug.
2. Description of the Prior Art
Low back pain has been a leading cause of industrial disability and a source of enormous economic loss to individuals, corporations and insurance companies. The leading cause of this disability has been from rupture or degeneration of lumbar intervertebral discs. Pain in the lower extremities (sciatica) is caused by compression of spinal nerve roots by damaged discs between the vertebrae and low back pain is caused by collapse of the disc and adverse effects of bearing the majority of the body weight through a damaged unstable vertebral joint. In the past clinical attention has focused on relief of the sciatic pain by removal of pressure from the nerve root. Less success has been achieved with treatment of the low back pain. These surgical treatments have fallen into the following groups: